postgresql query user

SELECT u.usename AS "User name",  u.usesysid AS "User ID",  CASE WHEN u.usesuper AND u.usecreatedb THEN CAST('superuser,create
database' AS pg_catalog.text)
       WHEN u.usesuper THEN CAST('superuser' AS pg_catalog.text)
       WHEN u.usecreatedb THEN CAST('create database' AS
pg_catalog.text)
       ELSE CAST('' AS pg_catalog.text)
  END AS "Attributes"
FROM pg_catalog.pg_user u
ORDER BY 1;